trust in the LORD
The command "trust in the LORD" is a central theme throughout the Psalms and the entire Bible. The Hebrew word for "trust" is "batach," which conveys a sense of security, confidence, and reliance. Trusting in the LORD implies a deep, unwavering faith in God's character, promises, and sovereignty. In the historical context, Israel often faced external threats and internal challenges, and this exhortation serves as a reminder to place their confidence not in military might or alliances, but in the LORD, who is their ultimate protector and provider.

He is their help
The phrase "He is their help" emphasizes God's role as a supporter and sustainer of His people. The Hebrew word for "help" is "ezer," which signifies assistance and support. This term is used in various parts of the Old Testament to describe God's intervention and aid in times of trouble. The historical context of Israel's journey—from slavery in Egypt to the conquest of Canaan—demonstrates numerous instances where God acted as their help, delivering them from enemies and providing for their needs. This assurance of divine help is meant to inspire confidence and peace among the faithful.

and shield
The word "shield" in Hebrew is "magen," which refers to a protective barrier or defense. In ancient times, a shield was a crucial part of a warrior's armor, providing protection against enemy attacks. By describing God as a "shield," the psalmist conveys the idea of divine protection and security. This metaphor is used throughout the Psalms to illustrate God's safeguarding presence over His people. In a spiritual sense, God as a shield implies that He defends His people from spiritual and physical harm, offering refuge and safety amidst life's battles. This imagery reassures believers of God's constant protection and care.

He is their help and their shield.--The original form of this motto of trust appears in Psalm 33:20. Here the change of person suggests some musical arrangement. Apparently one part of the choir, or, it may be, one officiating priest, addressed successively the whole congregation with the charge, "trust in Jehovah," and each time the full choir took up the refrain, "He is their helper and shield," repeating to the priest the ground on which he urged confidence and loyalty. Then in Psalm 115:12-13 congregation and choir join, changing to the first person.